Pyrrolidone is particularly useful as an intermediate in the preparation of Nylon-4, in the preparation of N-methyl pyrrolidone and N-vinyl pyrrolidone which are useful as organic solvents, and in the formation of polymers which have certain specific properties. Heretofore, pyrrolidone has been prepared from succinonitrile by various processes utilizing high pressures of hydrogen. For example, according to U.S. Pat. No. 3,095,423 2-pyrrolidone is prepared in a liquid phase process comprising the simultaneous hydrogenation and hydrolysis of succinonitrile utilizing aqueous ammonia and hydrogen pressures of at least 500 psi, and preferably hydrogen pressures of from 1000-2000 psi. U.S. Pat. No. 3,781,298 also describes a single step process for preparing 2-pyrrolidone by hydrogenating succinonitrile in an aqueous solution but at pressures greater than 2000 psig. U.S. Pat. No. 3,644,402 discloses a two-step process for hydrolyzing and hydrogenating succinonitrile sequentially, wherein the hydrolysis reaction is conducted in aqueous ammonia and the hydrogenation in the presence of a nitrogen-containing basic organic solvent at pressures of from about 750 to 3000 psi. None of the processes of the prior art, however, teach that considerable improvement in the yields of pyrrolidone can be obtained by the process of the instant invention utilizing hydrogen pressures below 500 psi.